1. Technical Field
The present invention relates generally to an apparatus for manufacturing ice. More particularly, the present invention relates to a unique construction for an evaporator plate assembly for use with the apparatus for manufacturing ice.
2. Discussion
Automatic ice making machines are commonplace. These ice making machines are found in food and drink service establishments, hotels, motels, sports arenas and various other places where large quantities of ice are needed on a continuous basis. Some of these ice making machines produce flaked ice while others produce ice shaped in a variety of configurations which are generally referred to as cubes. The present invention relates to an ice making machine that produces ice which is shaped in one of these various configurations or cubes.
Automatic ice manufacturing machines generally include a refrigeration system having a compressor, a condenser and an evaporator; a series of individual ice forming locations which may or may not be referred to as pockets; and a water supply system. In a typical ice manufacturing machine the evaporator section of the refrigeration system is connected to the series of individual ice forming locations so that these individual ice forming locations are directly cooled by the refrigeration system. Water may either be supplied to fill these ice forming locations if they are in the form of a series of pockets or water may be supplied to these ice forming locations by having the water trickle over or be sprayed onto the individual ice forming locations. The run-off of this trickled or sprayed water is usually recirculated within the water supply. The trickling or spraying methods of supplying water is normally preferred because these methods will produce clear ice while the static filled pockets method generally will produce white ice.
Automatic ice making machines are normally controlled by the level of supply of the ice in the storage portion of the ice making machine. When the supply of ice in the storage portion is insufficient, automatic controls cycle the ice making machine through ice production and ice harvest modes to supplement the supply of ice in the storage portion. In the production mode, the refrigeration system operates in a normal manner such that expanding refrigerant in the evaporator removes heat from the series of ice forming locations, freezing the water to form an ever growing layer of ice. When the ice thickness reaches a predetermined condition or a specified time period has elapsed, the ice making machine switches to harvest mode. Typically the harvest mode involves a valve change which directs hot refrigerant gasses to the evaporator. The ice forming locations are heated by the hot refrigerant gasses until the ice in contact with the evaporator begins to thaw. Normally some type of mechanism ensures that a vacuum is not formed between the individual ice pieces and the evaporator which normally involves the introduction of air between the individual ice pieces and the evaporator surface. Once the ice eventually falls from the evaporator, the valving on the refrigeration system is changed back to its original configuration, the production mode, and thus the cycle begins again. The ice making machine continues to cycle between the production mode and the harvest mode until some type of sensing system in the storage portion signals the refrigeration system to pause.
Current evaporators have been created by bonding evaporator tubes and partitions to a base wall. The evaporator tubes and the base wall are normally made of copper which is then given a nickel plating which shields the ice from the copper material. The forming of the copper tubes can create residual stresses in the material that may cause cracks. Additionally, the nickel plating which shields the ice from the copper material can flake off of the copper tubes. These types of evaporators have performed satisfactorily but they are relatively expensive to manufacture.
Moreover, some current evaporators are assembled through the use of a solder process. Evaporators assembled through this solder process can easily separate if water leaks into the internal surfaces of the evaporator when the unit is in its ice making mode. The maintenance expense relative to these types of evaporators is rather costly.
In order to overcome the problems associated with evaporators manufactured from tubes, partitions and base walls, and assembled through the use of a solder process, various designs of evaporators manufactured from sheets of stainless steel and assembled through various bonding methods have been developed. The stainless steel sheets are stamped into various configurations which permit refrigerant flow throughout the evaporator. The continued development of the stamped stainless steel evaporators has been directed to designs which simplify the manufacturing process and the assembly of the evaporators while keeping costs at a minimum and performance of the evaporator at a maximum.